you would have to pick up a auto meter setup and you could pull the PTO plate off and weld in a little bung on the lower corner of the plate for the temp sender and re install every thing, it probably would be a good think to know the temp , i know i have gotten mine nice and toasty a few times
rumor is the ford guys have a cooling setup in their ZFs from the factory but i still haven't come across a ford that i can crawl under that has a zf to take a look herd that is has a little pickup tube that goes throu the pto plate has a small electric pump , (dont recall if it went thou the engine radiator or had its own little one) then returns back thro the pto plate.
and duratothemax is right im purity sure you cant take a Allison dash (with the temp gauge) and make it work factory stile on your zf truck